What year was the green jersey introduced in Tour de France?

Explanation

In Tour de France, the rider who leads the sprinting competition wears the green jersey. In 1953, a points competition was introduced in Tour de France, and as the sponsoring company, Belle Jardinier, sold garden tools, green was an obvious colour choice. One year, in 1968, the jersey was red instead of green, due to demandds from a new sponsor. The year after, however, the jersey was green again and has remained so ever since.